Electric heating unit



April 14, 1925. 1,533,293

J. c. WOODSON ELECTRICHEATING UNIT Filed March '13, 1924 2 sheets-"sheet 1 INVENTOR WITNESSES? I H qjafiwm :1

as 24 James C Woodaon 1 52:: BY M wl 15% :1 l l ATTORNEY ril 14,1925. 1,533,293

J. C. WOODSON ELECTRIC HEATING UNIT Filed March 13, 1924 2 Sheets-Sheet 2 as, I 5 5! 1 m n I! II I! ll ll n 1| H II III I l \1 n I I I P \i-jggvgcy aa WITNESSES: INVENTOR James CZM/oadsan S S I 7 BY S V ATTORNEY Patented Apr. id, 1225.

are ea J C. WOOIDSUN, OF EAST PITTSBURGH, PENNSYLVANIA, ASSIGNOR T0 WESTHIG- HOUSE ELECTRIC 6; MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA.

ELEG'IREG HEATING UNET.

Application filed March 13, 1924. Serial No. 698,871.

To all whom it may concern:

Be it known that I, JAMEs C. Woonson, a citizen of the United States, and a resident of East Pittsburgh, in thecounty of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Electric Heating Units, of which the following is a specification.

My invention relates to electric furnaces and particularly to electric heating units therefor.

One object of my invention is to provide a substantially self-sustaining heating unit for a furnace that shall be movable as a unit into and out of the furnace structure.

Another object of my invention is to provide a heating unit that shall be movable into and out of the furnace chamber in av positions by means integral with the furnace structure.

l-leretofore, removable heating units for electric resistance furnaces have usually comprised a resistor member, refractory supporting and spacing members and metallic tie-rods or frames. Such self-contained heating units were relatively complicated and expensive and had an appreciable heat storage capacity. In view of these disadvantages, it provide in my present inven- 'tion a substantially self-sustaining and removable heating element, the number of whose component parts has n reduced to a minimum;

In the drawings,

Figure 1 isa front elevational view of an electric resistance furnace embodying my invention, the heating units being illustrated in the positions occupied by them during their movement into the furnace structure.

Fig. 2 is a front elevational view of an electric resistance furnace embodyin my invention, the front cover or door dieing removed,

Fig. 3 is a fragmentary view of a modified form of construction embodying my invention,

Fig. 4 is a perspective view, of a complete ,heating unit and of a partial heating unit comprising a part of the device embodying my invention, 7

Fig. 5 is a top plan view of a refractory spacing member,

Fig. 6 is a front elevational view of the refractory member shown in Fig. 5,

Fig. 7 is a top plan view of a refractory spacing member,

Fig. 8 is a front elevational view of the refractory member shown in Fig. f,

Fig. 9 is an end elevational view of a refractory resistor-supporting and locking means,

Fig. 10 is an end elevational view of a modified form of resistor locking, supporting, and spacing means,

Fig. 11 is a top plan view of the spacing means shown in Fig. 10, i

Fig. 12 is an end elevational view of a refractory bar and Fig. 13 is a front elevational view of a refractory spacing bar comprising a part of the device embodying my invention.

An electric resistance furnace structure 21 is shown in Figs. 1 and 2 of the drawings as being substantially rectangular in lateral cross-section and comprising a plurality of bricks or blocks 22 of a suitable refractory high-temperature resisting and heat-insulating material usually employed in the art.

tially rectangular in lateral cross-section.

The bricks or blocks 22 are so located and spaced apart as to enclose a furnace cham-. ,ber' 23, here illustrated as being substan- As the particular type of materials and method of assembly thereof forms no particular part of myinvention, the furnace structure has been illustrated schematicallyv only.

A heating unit 24 comprises a relatively heavy resistor wire or rod 25 that is initially preformed to comprise a plurality of substantially straight, and arallel-exiendi portions that are severay connected by return-bent portions as is illustrated more particularly in Fig. 4 of the drawings.

Afterbeingpreformed to comprise a pluralit of return-bent portions located in a sing e plane, the resistor member 24 is bent so that the two integral portions thereof are located in two intersecting planes located at substantially right angles relatively to each other, as is illustrated not only in Fig. 4, but also in Figs. 1 and 2 of the drawings,

where the resistor member is shown in front 1) view only.

,The point at which the preformed resistor wire is bent is, of course, selected in accordance with the dimensions of the two intersecting surfaces or walls of the furnace structure against which the resistor member thus bent is to be located.

The rear end-part 26 of the resistor meanber 24 is preferably bent at right angles to its integral and adjacent portion. The

other end portion 27 of the resistor member.

25 may extend laterally of the heating ele ment, as illustrated in Fig. 4 of the drawing or it may be bent at right angles to the integral and adjacent portion and in a direction substantially opposed to that in which the end portion 26 extends.

The heating unit 24: is moved into its 'proper operative position in the furnace chamber 23 longitudinally thereof and angularly displaced from its proper operative position which it is to occupy within the furnace chamber, and supported by means integral with the furnace structure and to be hereinafter described. A plurality of refractory bars or elongated blocks 28, of a suitable high temperature-resisting and electric-insulating material, are built into the furnace structure and supported by the roof part thereof adjacent to, butspaced from, one of the upper corner portions thereof, as illustrated in Figs. 1 and 2 of the drawings, and project into the furnace chamber.

Asubstantially similar member 28 is located in the floor portion of the furnace structure'adjacent to but spaced from the opposed and lower corner of the furnace structure. The member 28 is provided in one of its 'side faces with a plurality of spaced pockets 29 therein that are alined longitudinally of the member 28. The bars 28 may be of any suitable or desired length, and extend for substantially the entire length ofthe furnace chamber,-or for such a portion thereof as is to be covered by the heating units. 3

A plurality of elongated, refractory bars 31, illustrated more particularly in Fi 7' and 8 of the drawings, are built into t e furnacestruct-ure, in the "roof and the floor thereof respectively, and are located adjacent to but spaced from the opposite corner portions of the furnace structure, as

illustrated in Figs. 1 and 2 of the drawings.

The bars 31 are relatively narrow and are provided with a plurality of laterally extending grooves 32 in one edge thereof, the distance between the grooves 32 being in accordance with the distance between the adjacent integral and parallel extending portions of the resistor member 2st. The bars 31 are so mounted that the edge having the groves 32 projects into the furnace cha1n In order to permit of moving a heating unit 24 into its proper operative position in the furnace chamber 23, it is necessary to provide a longitudinally extending groove or slot 33 in one corner of the furnace structure, as is illustrated in the upper right hand corner and in the lower left hand corner of the structure in Fig. 1 of the drawing.

The dimensions of this groove 33 and the dimensions of the heating unit 2-l are such that the heating unit may be moved into the furnace chamber by angularly displacing it from its final and normal operative position within the furnace chamber, as illustrated more particularly in Fig. 1 of the drawings. The end portion 26 of the resistor member may be caused to move through a suitable opening (not shown) in the rear wall of the furnace structure, while the heating unit is being moved into substantially its proper operative position laterally of the furnace structure.

After the heating unit has been moved into the chamber 23 as far as necessary, the

end or side portion thereof, the return bent portions of which are to be located in the pockets 29 of the abutting and alined members 28 it is so moved beyond the outer surface of the member 28, as to permit of in serting the respective return bent portions thereof in the co-operating pockets 29, a position that is illustrated in the upper right hand corner of Fig. 1 of the drawing, particularly by the left hand heating unit.

The depending portion of the left hand heating unit may then be raised to substantially the position illustrated in Fig. 2 of the drawings, the straight and parallel-extending portions of the heating unit fitting into the groves or slots 32 of the respective spacing members 31 located in the roof and in the left hand side wall'of the furnace structure. A locking bar 34 is then moved longitudinally of the slot 33 into the furnace structure, as is illustrated more particularly in Fig. 2 of the drawing, and serves not only to hold or look the heating unit in its proper operative position relatively to the furnace structure butalso to support it thereiii. The bar 34 is provided with a longitudinally extending ridge to prevent outward movement of the ends of the resistor member.

A plurality of alined'and abutting corner blocks 35, having angularly disposed faces radiate heat directly intothe furnace champrojecting into the furnace chamber are berwithout it having to traverse a mullie provided in those corners not occupied by the supporting means 34, these blocks being 'operatively engaged by the intermediate bent parts of the integral portions of the heating unit in order to hold it "sub- 'stantially tightly .in its proper operative position in the furnace structure.

Referring more particularly to the construction illustrated in the fragmentary view in Fig. 3 of the drawings,'I emplo the refractory spacing and supporting b ocks 28, to support the end parts of the horizon tally extending portions of the heating unit 24, as hereinbefore described. Corner blocks 36 are provided in the opposing corners of the structure heretofore occupied by the blocks 35. .The blocks 36 are prov idedwith a plurality of symmetrically spaced grooves 37 extending across the angularly disposed surface thereof thzit-normally projects into the furnace chamber 23. 'The distance between the grooves 37 .is such as to co-operate with and receive the bent parts ofthe heating unit 24'and to-hold them in proper operative and spacedlpositions relatively to each other.

The vertically extending portionsof the heating units 24 are supported and held in properly spaced positionsrelatively to each other by aplurality of refractory bars 38 that are severally provided with a plurality of spaced pockets 39 located in alined position in one face thereof, as illustrated more I particularly in Fig. '11 of the drawing.

The return-bent portions of the heating units 24 fit into the pockets 39 and are thereby prevented from. movement both longi-.

tudinally and: laterally ture.

a In Order to permit; of placing the bars 38 in' heir proper-operative position-sin the of the fiirnace strucgrooves 33, they are made relatively shallow and an auxiliary bar 41 is located underneath or above the bars 38, depending upon I taiuing. "therebetween,

order that they-may be whether the bar 38 is located in the floor ture. 1

Both of the bars 34 and 38 are prbvided with angularly' disposed side surfaces in held in the upper groove33. 1 f

The method of mounting a heating unit 24 in a furnace structure of the type disclosed in Fig 3 of the drawings, is substantially the same as was hereinbefore de-' sciibed in connection with the structure illustrated in -Fi 1 and 2 of the drawings. The device embodying'myinvention thus providesa heating unit that is supported at its" ends only and is substantially self-suswhereby i all of the length of the resistor member comprising'the heating unit is hareand may practically plate or a refractory support. I

The-supporting means for the. heating I unit are integral with'or are a portion of the furnace structure, whereby the number of component parts of the removable heating ,unit is reduced to a minimum, comprising and scope of the invention, Idesire' therefore that only such limitations shall be placed thereon as are imposed by the prior art. I a i y I claim as my invention 1, In an'electric' furnace, in combination, a resistor member comprising a plurality of return-bent integral portions, located in two angularl'y intersecting planes only.

2. In an electric furnace, in combination,- a resistor member comprising a plurality of integral, return-bent porti0ns,\a part of the length of each portion being located in a plane substantially at right angles to the other portion thereof. 5

of integral, return-bent portions located in two planes substantially 'atright angles to each, other. I

4. In an electric furnace, in combination,

- l o 3. In an electric furnace, in combination, 4 a resistor member comprising a plurality a resistor member comprising a plurality of integral, return-bent portions, located in two planes substantially atright angles to each other 'and means in said furnace for supporting 'said resistor member at only the ends of said portions.

a resistor member comprising a plurality of integral, return-bent portions located in two planes substantially at'right angles to each 5. In an electric furnace, in combination,

'ot er and resistorrsupporting means in said sistor longitudinally thereof, in an angularly displaced position relatively to itsproper operative position. 6. Inan electric integral return-bent portions, said portions being coated in adj acent planes and extending therein in two directions.

7. In an electric furnace, in combination,

ace permitting the insertion of said refurnace, in combination, a reslstor member comprising a plurality of ing therein in two directions, and means i for supporting said resistor at only theends thereof, 'the respective portions being substantially self-sustaining therebetweem 8. In an electric furnace, in combination,

a. resistor member comprising a plurality of integral return-bent portions located in two planes substantially at right angles to each.

other, and refractory means integral with 4 other.

9. In an electric furnace, in combination,

a preformed and substantially self-sustainingresistor member, movable as aunit into said furnace, aIfd *means for locking said resistor member-in its proper operative position in said furnace. a

, 1O.'In an electric furnace, in combination, a preformed and substantially self-sustain-- ing resistor member, movable as a unit into sa1d furnace and a single refractory bar; for locking said resistor member inwits proper operative position in said furnace.

11. In an electric furnace, in combination, a preformed and substantially self-sustaining' resistor member movable as a unit into said furnace, and a locking bar for holding said-resistor member in its proper operative position, said bar being removable to permit of moving said resistor into said furnace;

12. ,In an electric furnace. in combination, a preformed and substantially self-sustaining resistor member movable as a unit into' said furnace and a single means for maintaining sa1d resistor member in its proper I operat ve positionin said furnace.

13. In an electric furnace, in combination,

a preformed and substantially self-sustaining resistor member movable as a unit into V ing resistor member movable as a unit into said furnace angularly displaced from its normal operative position, and a locking bar for holding said resistor member in its proper operative position, said bar being remov- 7 able to permit of moving said resistor into said furnace longitudinally thereof.

15. In an electric furnace, in combination, a substantially self-sustaining resistor member preformed to comprise a plurality of substantially parallel-extending integral portions having return-bent end portions,

and a refractory bar for holding said resistor member in" its proper operative pos tion in said furnace and for holdlng said return-bent portions at one end of said resistor member in proper operative positions relatively to each other.

In testimony whereof, I have hereunto subscribed my name this 5th day of March,

JAMS O. WOODSON. 

